In the past decade, dramatic advances in the understanding of HIV and its therapy have transformed HIV into a chronic, treatable disease. These advances, however, raise critical and complex questions linking basic research, clinical epidemiology, clinical trials, and outcomes research. The goal of the Harvard Program for AIDS Clinical Research Training (PACRT), which has successfully trained clinical investigators for 14 years, is to provide br6ad training in quantitative research methodologies and a closely supervised "'research experience to infectious disease and other physicians at an early stage in their careers, as well as to pre-doctoral PhD students whose focus is on HIV clinical research. This training will prepare both groups to conduct clinical research of the highest quality and of direct relevance to the prevention and treatment of HIV infection, and it will prepare them for the next phase of development as independent investigators. The post-doctoral candidates will receive two years of research training under the close supervision of one or more of the 15 program faculty members. Program faculty include internationally recognized investigators in the fields of clinical virology, epidemiology, clinical trials, decision-analysis, cost-effectiveness analysis, outcomes research, and medical anthropology. Both pre-doctoral and post-doctoral trainees will receive didactic training through coursework at Harvard School of Public Health or other Harvard University sites. Primary performance sites for the post-doctoral fellows will be the Massachusetts General Hospital, Beth Israel Deaconess Medical Center, Brigham and Women's Hospital, and Harvard Medical School. In its first 14 years, this program has helped develop and launch a new cadre of independent investigators studying a broad array of clinical research issues in HIV. It's trainees have published over 100 peer reviewed manuscripts, and the success of its fellows in obtaining continued NIH support places it among the top programs in the country. The proposed continuation will allow the PACRT to help train the next generation of highly successful investigators to address the complex and evolving issues arising today in HIV clinical research.